设等差数列﹛an﹜﹛bn﹜的前n项和分别为Sn,Tn.且Sn/Tn=n-9/5n-9.则a8/b8=?
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设等差数列﹛an﹜﹛bn﹜的前n项和分别为Sn,Tn.且Sn/Tn=n-9/5n-9.则a8/b8=?设等差数列﹛an﹜﹛bn﹜的前n项和分别为Sn,Tn.且Sn/Tn=n-9/5n-9.则a8/b8
设等差数列﹛an﹜﹛bn﹜的前n项和分别为Sn,Tn.且Sn/Tn=n-9/5n-9.则a8/b8=?
设等差数列﹛an﹜﹛bn﹜的前n项和分别为Sn,Tn.且Sn/Tn=n-9/5n-9.则a8/b8=?
设等差数列﹛an﹜﹛bn﹜的前n项和分别为Sn,Tn.且Sn/Tn=n-9/5n-9.则a8/b8=?
a8/b8
=15a8/15b8
=(a1+a2+a3+...+a15)/(b1+b2+...+b8)
=S15/T15
=6/66
=1/11
S15=15A8
T15=15B8
A8/B8=S15/T15=15-9/75-9=6/66=1/11
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